US 2803545 A
Description (OCR text may contain errors)
Ailg- 20, 1957 o. w. RANDOLPH 2,803,545
DEHYDRVATION Filed Feb. 4. 1954 2 Sheets-Sheet 2 ily.
Unite DEHYDRATIGN Oliver W. Randolph, Toledo, (lhio, assignor, by mesne assignments, to A. T. Ferrell -& -Co., Saginaw, Mich, a corporationofMichigan Application February 4, 1254, SeriaiNo. 408,275
Claims. (Cl..99--8) content is retained therein.
Another object is to produce a dehydrated vegetable food of "fine homogeneous and uniform particles which is appetizing as an animal feed and is adaptable to 'be stable .for extended periods of storage.
Generally speaking,.the. system of this invention comprises thoroughly co-mingling vegetation material with two separate streams of hot combustion gases in'two successive stages. These streams of combustion gases are snfficiently'hot to effect approximate instantaneous leaf withering of the leafy portions of the vegetation by removing the water or moisture vapor from them at a rate sufiicienttoquenchqany tendency for their combustion. =The:heat of these gases also simultaneously comminutes the leafy particles .so they remain in suspension in the hot gas streams, :while theheavierparticles such as the stems, fall intonanagitator where they are mechanically comminutedrandthrownback into the stream of hot gases with theususpended leafy particles. The introduction of the vegetation into the hot gas streams is accomplished in both stagesqbyua. means to project the material parallel toand above-thehotgas st-reams, so that the streams will .lt eep in suspension ash-much of theparticles of the vegetationuas'possible-and thereby convey the particles through .the apparatus. .At the end of each of the-two successive .heat .treatingwstages, the excess combustion gases are sep- .arated from the .particles, such as in'cyclone separators,
tbefore -they are further treated including their'introduction into the second freshhot combustion gas stream.
After the particles have been dried in the two successive .sta ges,'they-may be :further divided, co-mingled and/or separatedaspdesired, including'treatment in a hammermill. The system of this inventiontmay be arranged to be substantially continuous and may include special :feeding means for distributing intermittent truck loads of vegetation.
The above mentioned and other'features and objects of this invention and the manner of obtaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment. of the invention taken in conjunction with the accompanying drawings, wherein:
Fig.1 isa schematic planview of a specific installation of .the dehydration apparatus of this invention for receiving fresh three and four inch length cuttings of a chopped forage crop .material as it comes directly from a field.
2,803,545 Patented Aug. 20, 1957 Fig. 2 is a schematic sectional -view taken alongline II-II ofFig. 1 in the direction of'thearrows, showing part of the foliage distribution apparatus for feeding'the treating equipment of this invention;
Fig. 3 is a schernatic section taken alongline III- HI of Fig. 1 in the direction of the arrows, showing leftend of the distribution and feeding apparatus of Fig. 2 and a vertical section through one end of the first drying :section or chamber of the treating equipment;
Fig. 4 is a schematic vertical sectional view taken-along line 'IV--IV of Figs. 1 and 3 in the direction of themrows, showing the kicker for projecting the material into the first drying chamber or section above-and parallel to the hot combustion-gases projected into thatchamber;
Fig. 5 is a side elevation of the second. part of treating equipment shown in Fig. 1 taken along'line V--V'in the direction of the arrows,-showing the third. and'fourthheat treating chambers or sections and spacer between-them, as well as the cyclone gas separators and a 'hammermill as a final treating stage;
Fig. 6 is a schematic vertical section taken along line VI-VIof Fig. 5 in the direction of the arrows, showing a rotary valve'and particle dischargingmeans and-a spe Fig. 7 isa vertical section taken along line VlI--VII of Fig. 6 in the direction of the arrows showingnthelhammermill with partsthereof being broken away;
Fig. 8 is a partialhorizontal section taken along.line Vlll VllI of the discharge ducts at the bottom of the hammermill of Figs. 6 and 7;
Fig. 9 is an enlargedperspective view oftwoadjacent material impact-receiving breaker bars mountable for orienting and replacement in the hammermill of Fig. 6 with parts thereof being broken away; and
Fig. 10 is an enlarged perspective view ofa freely swingable reversible mountable hammerfor the hammermill shown in Figs. 6 and 7.
From afield there may be brought in freshly cut .or harvested vegetation, as aforage crop fresh or green cuttings 1 (Fig. 2), say of alfalfa, such being chopped up or in lengths running under 4" long. The material 1 to be treated as conveyed by a truck is dumped into a receiver or hopper 2*(Figs. 1, 2). A motor 3 (Fig. 1) has control-of-speedconnection ,to a shaft 4 actuating an.endless conveyor 5 providing a movable floor or bottom extending from the chute orhopper 2 to an elevator or flight carrying type of conveyor 6 actuated at a predetermined speedby ;a motor 7 to regulate the amount of material fed into the treating equipment.
From the motor 3 is a transmission connection 8 to a shaft (Fig. .2) having thereon a high-speed rotation kicker or thrower 10, acting to swish 01f the traveling floor 5 the pregauged thickness, of say /2" of chopped alfalfa 1 thereon,,so as tohave such material well distributed when it falls onto the elevator 6 in its upward course. 'From the shaft 4 (Fig. l) is a transmission ii. to a shaft 12 opcrating upwardly inclined lower reach of an endless belt device 13 (Fig. 2) having flights. or kickers 14, effective to skirnback. along the floor 5 reverselyto its travel direction, surplus of the choppings 1 as may be in excess of the set thickness of the materialto be passed to the throwing device 10. Thus there may be husbanded in the hopper 2 sufficientmaterial 1 for continuity of uniform feeder supply by the elevator 6, even between truck loads, as well as to cover intermissions in such deliveries.
A hood or housing 15 (Fig. 3) directs discharge of the choppings 1 from the upper end of the elevator 6 to fall on a kicker or throwing means 16 (Fig. 4) driven at .a high speed by a motor 17 (Figs. 1, 3). The bulk material fragments 1 are thus projected thru a window or horizontally directed .material supply port 18 as a sus- 3 pension scattering into upper zone or region 19 of the first drying chamber (Fig. 4).
A furnace, as for gas or oil may have a burner 20 or I 20 (Figs. 1, 5) operating in a combustion chamber 21 (Fig. 4) having a firebrick lining 22 '(Fig. 4) in a heat insulation jacket 23 (Fig. [4) assembled as a furnace unit 24 or 24 (Figs. 1, 5) having a base section 25 (Fig. 5) for air draft 26 (Fig. 5) intake to its burner 20 shown in Fig. 5 or burner 20 shown in Fig. 1.
The furnace unit 24 or 24 (Figs 1, 5) has a duct forming passage or connection 27 (Fig. 5) locating the combustion chamber which has therefrom a horizontally directed gas supply discharge port 28 (see Fig. 3 and 4) which provides a particle suspension medium of moving heated gases active in the zones 19 (Fig. 4) of the body or the housing or chamber sections 29 or 29' Figs. 1
V and 5) of the particle comminution type of dryer or centrifugally throwing beater or mill of this present invention.
organic material which is held in suspension in the hot combustion gases and is reduced to particles which are co-mingled longitudinally and transversely with the gas stream by heaters 36 provided in the lower portion 31 of each of the drying chambers or sections 29, 29a, 29, and
29h (Fig. 1). In order to minimize heat loss throughout the multi-sections of the dryer of this installation, an insulation jacket 30 (Fig. 4) is provided around each of these sections 29, 29a, 29', and 29a. The dryer or dehydrator zones 19 (Figs. 3, 4) have downward therefrom subzones or lower chamber portions 31 (Fig. 3) in the lower base sections 32 and 32 (as shown in Fig. 5 below sections 29 and 29a). Splicers or spacer sections 33 and 33 (Figs. 1 and 5) provide continuity for the zones 19 of each of the sections 29, 29a, 29 29a, respectively, as well as acting as means to direct upwardly the material from their lower portions 31 into the upper zone or portion 19 of the following section for further co-mingling with the gases and material in that zone 19. The clearance between the lower portions of the sections 29-29a and 29'--29a (Fig. 5) provides space for between-section bearings 34 to mount shaft 35 to carry the high speed rotating kickers, fans, or comminuting members 36 in the bottom of each of the chambers (Fig. 3) actuatcd by the motor 37 (Fig. 5).
Considering the material 1 as short cuttings of alfalfa,
A there is considerable leaf volume on the short stern sections. There is high protein value in the leaf particles, which, as thrown by the impeller or kicker 16, have suspension augmented by the high draft rate of the furnace discharge, which discharge draft may have a temperature in the zone 19 even up to 1250 to 1800 F. The high moisture initial content of the forage may be in the range of 70% to 80%. The moisture is quickly converted to steam in such dominance as to squelch or blanket combustion action on the forage, with the withered unscorched leaves retaining normal approach to green color and high vitamin values. The lightness or low specific gravity for the leafy portions results in it being -out, or descend into the zones 31 is counteracted by the fans 36, supplementing the kicking with some beating to thereby promote breaking or subdividing of the fiber.
As the vegetation material and fibers of the stems are subjected to drying, comminuting, and general reduction in dimensions, their relative surface areas are correspondingly increased so that the high temperature combustion gases with which they are co-mingled correspondingly extract more moisture from the vegetation particles. Furthermore, the air intakes 26 to each of the furnaces 24 and 24' are regulated so that no large excess of unburned air is present in the hot combustion gases which are directed through port 28 from the furnace. These completely burned gases, plus the stream produced from the moisture which was present in the now dried vegetation, prevents any combustion in the drying chambers from taking place, since the percentage of steam present in the drying chambers including superheated steam, is comparatively great.
Upon the basis of green forage carrying close to moisture and supplied to the dehydrator at the rate of say per min. take off at 50% per min. moisture at a section 39 or 39 (Figs. 1,5) from the region of lower portion of the zone 19 (Fig. 3), means that the moisture content is brought down close to 40%.
While the fans 36 have from the beating actions a measure of breaking up or subdividing in promoting the drying, the explosion approaching action of imparting above-boiling temperature to the moisture-carrying material has effected so-called flash-boiler action for spontaneous steam generation in clearing the more-readily released moisture from the forage, with resulting shatterings of leaf and even stern forms. Accordingly there is very material subdivision toward fines from the 4' cut tings of the supply to the hopper 2.
The first section 39 (Fig. 1) is an axial supply or intake to a blower or centrifugal fan 40 actuated by a motor 41. The section 39 has its intake draft from the chamber zone 19 of the second dryer 29a of such velocity as to act as an induced draft device in promoting mixing intake therewith of flow from the take-off duct 38. There is thus an automatic mixing of the leafy fines and the stem subdividings for upflow transfer by the fan 40 by way of a duct 42 to a cyclone separator or dust-collector 43 (Figs. 1, 5, at the left). As there may be some pressure buildup from the generated steam in moisture extraction, with possibly some dilution from products of combustion, flow-off 44 is provided therefor from the cyclone 43.
The particles, separated from the vapor and gas portions by the cyclone 43, are delivered directly to a second impeller or projector 16 (Fig. 5) between the furnace 24 and the third dryer 29 which kicks such fines into the upper chamber zone 19 of the third dryer comminutor or drying section 29', wherein a second furnace 24' provides heat source for the third and fourth dryer chamber portions 29 and 29a. The finer and lighter particles are more rapidly carried through the third and fourth sections 29' and 29a, in their upper zones 19 (Fig. 3); with the less light or heavier particles tending to settle or work toward the lower zones 31, with the up-throwing action of the fans 36 effecting further subdivision as the re-supplied high temperature combustion gases have effected further moisture removal attack on the greatly increased surfaces of the further divided particles. Current practice as herein disclosed brings the moisture content down to the range of 8% where the second section 39 (Figs. 1,5) induces fines flow from the second take-off duct 38 to intake to the second blower or fan 40 for up-draft duct 45 -to deliver to a second cyclone dust collector 46 having a vapor discharge 44.
The cyclone 46, as the second vapor take-off device, has the fines therefrom pass by a down-passage 47 to be spread by an inverted V-baffie 48 (Fig. 6, upper portion). A motor 49 (Fig. 5) operates an agitator 50 (Fig. 6)
in the down-passage 47 below the stream spreader V- device 48. A motor 51 (Fig. 5) drives a rotary valve type of feed device 52 (Fig. 6) having a shield chute fixed side way 53 at the up-rotation side for the rotor 52,
and an adjustable chute-side leaf 54, adapted to beset at various clearances by the notched arm '55. The high speed of clockwise (Fig. 6.) rotation'ifor the valve 52 tends to throw any heavier or foreign matter to lodge on an incline 56 and passout of a window 57 .as detritus particles 58. A shield 59 for the window 57 tends to direct suction or in-draft across the incline 56 upper edge. An adjustableflap 560 at theopposite side is set to check suction or intake .draft atla port 61. The supply from the second cyclone .duct collector 46 of fines clear of-foreign matter is now in .course for. further subdivision.
With the temperature of the materialttothe first cyclone 43 (Figs. 1,5) in the .range of up to.250 F. there may be approximately similar temperature for the .fines at the second cyclone 46. The cyclone 43:has not brought down the temperature for the particles to the third and fourth comrninutors en route tothe second cyclone to disturb the initiated condition .of vaporizationbrought into the equipment at the first .comminutor. Therontinuity in the drying, say .to 6Vz% moisture content, achieves what would-not otherwise be possible due to the cooperative interaction for bringing rating in the range of 192,000 vitamin A in a food item carrying 19.1% fiber and 18.6% protein. There may 'be promoted further drop in temperature from toutsidetair. intake at the ports 57, 61, (Fig. 6) as the passage '47delivers fines to fall on at lower or second inverted =V-bafile 48 (Figs. 6, 7). There may be the divided :direct flow therefrom to an abrader or hammermill for further promoting the exposed surface ratio in dehydratingeificiency. The fiber content is reduced by high speed throwing action of a valve device to be wiped from face-64:to pass to a chute For arnill there is provided .aipair .rof concave plates .orrsections 66, 67 ,(Fig. 6). Adjacent the end of the underside of the bafiie 48' at one end is a hinge 68 for an outer shield section 69 for the plate 66. Similarly adjacent the valve device 63 is a hinge 68 for a shield section 70 for the plate 67. The plates 66, 67, have junction with a semi-cylindrical lower screen or perforate section 75 in the range of say 16 openings per inch. Considering this drum or shell to be in the range of 29" long and 43" in diameter, the upper plates are set back slightly to have lengthwise thereon breaker bars 71 with radial holes 72 (Fig. 9) so that a plurality of bolts 73 thru the plates 66, 67, may mount these bars in parallel either side up or exposed. While with the device 63 (Fig. 6) designed for clockwise rotation, in the event such be omitted, there may be reversal of the direction when there is rotation of a shaft 74 coaxially of a screen 75. On the shaft 74 (Fig. 7) disks 76 have rods 77 on which are strung swing hammers or arms 78, spaced by Washers 79. Holes 80 (Fig. 10) in opposite ends of the arms 7 8 permit reversal of the swing axis mounting for the arms on the rods 77.
At the clockwise direction of rotation for the shaft 74, the oblong rectangular or sharp comer-carrying arms 78 have the trailing clockwise direction corners swinging across the mesh screen 75 and toward the counter-clockwise corners of the parallel breaker bars 71. When there has not been use of the device 63, motor 81 (Fig. to drive the shaft 74, may be reversible, thereby causing the slight wear-down of corners on the arms 78 and the bars 71 to be on the corners un-affected by the clockwise rotation of the shaft 74. This use is achieved without any shifting of the arms or bars as to the mountings therefor. The disclosure means that four ways are available for wear action, by changing ends for the swing mountings of the arms 78, and by orienting of the bars 71, to have the opposite sides thereof toward the plates 66, 67. In the handling of alfalfa type of forage, the arms 78 may be A" thick, 1% wide, 5 long, with A clearance as to the screen and the bars 71, with the into Ia lower take-off section of two chamber portions 83 (Figs. 7, 8) with spread base Walls 84 eliminating central eddy accumulations.
From the base .portion of the housing 81' .of the hammermill .the chamber portions 83 have communication withanintake 85 (Fig. 5) to a .duct .86 to a third fan .or blower 40a. v'Il'hisfblower is on the shaft 74 and induces fines that passes through the screen 75 of mill to be carried from the blower 40a byaduct 87.
Considering the finished product to be: a feed material, the duct 87 is shown discharging into a third cyclone,
herein cyclone separator 88 having vapor discharge "44a,
effectiveunder-thepractice asherein conducted to bring thermal or feed to .a discharge 89 at a temperature of 80 or less with ,outdoor temperature in the range of .60 F. .Storingmay be thus had directly thru bagging device 90.
The particular instance, given as to material handling, green freshly cut alfalfa in chopped up lengths in the .rrangetof 4" long, '-has been efiicientl-ycarried thru for up to:t-wo tons per hour 50f output or dried product meal in the general dimension disclosed. The furnaces Hand 24' (Figs. :1, 5;) may bringthe combustion chamber 21 (Figs. 3,49 temperature up to in the range of 2300 F. With v300;.ou. .ft. per min. into thefirst and third sections 29 and 29 (Figs. 1, 5) there is in the range of four or five fold more vapor volume discharge at the exit 44 from the cyclone 43, considering the sections is the range of 7 high and upward of 3' width for the zone 19, sections 29, 29a, 29, and 29a each being about 8 long.
It is to be noted that subdividing is developed herein due to the flash supply of high temperature gas in thus exploding moisture from the forage, to an extent wilting or powdering the leafy portions, supplemented by the fan throwing to disintegrate the fiber portions. The second furnace heating stages carries further along in increasing the surface area, plus the hammermill taking on the still warm fines for completing conversion of the green forage into a finely subdivided fine meal food. Such quick carrying thru has been for the product to be in the range of 192,000 vitamin A rating at 8 /2 moisture, with 19.1% fiber and 18.6% protein.
While the bulk material taken into account more particularly herein has been forage crop, specifically alfalfa, range may be to inorganic material, as sand, marl, kaolin, meats, leaf and root crop vegetables, fruit, cereals, and mixtures. Values arise in the subdivision, in moisture removal to a standard for each, and the eificicnt carrying thru in the plural stage sequence. The hot blast action effects some structure shattering in vaporization, especially in reducing moisture. The subdivision experienced has been such that with sixteen mesh per inch for the hammermill screen 75, the materialas of body to be taken off at the discharge 90 (Fig. 5) has fines appropriate for grading as passing twenty mesh to the inch. The dehydration as disclosed promotes subdivision action. With leafy vegetation, the leaf-withering heat forthwith carries thru light fines in suspension. The fully ignited combustion vapors do not supply further combustion supporting atmosphere. While there may be excess of air supply, the moisture vapors effectively quench ignition of the material under going treatment, even tho such in itself is readily combustible in a normal atmosphere.
The feeder means is the effective kicker or horizontal throwers 16 and 16 (Figs. 3, 4). The treating means initially is the chamber, shown in sections, 29, 29a, 29', and 29a (Figs. 1, 5) with suspension zones 19 (Figs. 3, 4). The vapor dilution means is the combustion gas or vapor supply 28 (Figs. 3, 4) from each furnace 24 and 24'. The fans 36 (Fig. 3), as Well as the hammermill arms 78 (Figs. 7, are rotary material throwing members.
The cyclones or separator means 43, 46 (Fig. 1, 5), take off moisture vapor and products of combustion, with some temperature drop thereby controlled for delivery to the hammermill 81' (Figs. 5, 7). Vapor for suspension as well as bringing the product down to desired cooling is cared for at the windows 57, 61 (Fig. 6), in the downchute 47 from the cyclone 46 (Fig. 5). This cooling air dilution is removed by the cyclone 88 as the stage for material fines body product. The stems are the more coarse material in the sequence herein before reaching the mill 81' (Figs. 5, 7).
What is claimed and it is desired to secure by Letters Patent is:
1. A dehydration process for stem-carried leafy vegetation comprising: a horizontally directing draft of combustion vapor, horizontally directing vegetation particles to be taken on for suspension action in the direction of the draft and by the draft, said draft having a temperature sufficient to effect approximate instantaneous leaf withering of the leafy particles of the vegetation by removing their moisture vapor at a rate sufficient to quench any tendency for combustion of the particles during said suspension thereby also developing fine subdivided particles from the leaves, maintaining suspension of the stems in the draft by agitating and successively throwing them upwardly to promote their subdivision whereby said throwings of the stem particles are transverse to the relative general longitudinal progress of all the particles during their drying, said successive transverse throwings making the stem particles more fragile and developing them into more finely divided particles to approach a homogeneous product when co-mingling with the leafy particles, said process including, intermediate of at least two transverse throwings, the taking off of vapor from said draft followed by the introduction of more combustion draft horizontally with the movement of the particles.
' 2. A process according to claim 1 including the initial step of regulating the quantity of vegetation particles directed into said draft.
3. A process according to claim 1 including separating foreign material from the final resulting vapor separated material particles.
4. A process according to claim 1 including an additional step of further comminuting the final resulting dehydrated and vapor separated material particles.
5. A process according to claim 4 including separating foreign material from the resulting dehydrated vapor separated material before it is further comminuted.
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